Two members of the Senate’s Homeland Security and Governmental Affairs subcommittee on financial and contract oversight grilled National Guard leadership Thursday afternoon during a hearing on Capitol Hill to try and answer that.

“We need to measure the effectiveness of whatever dollars we do spend,” said Sen. Ron Johnson (R-Wis.) during the hearing. “This is one that I think should really get the caution flag.”

Major General Judd H. Lyons, who took over as acting director of the Army National Guard in January, said he was looking into the effectiveness of the Earnhardt sponsorship. The National Guard’s marketing and advertising budget is $120 million, meaning the NASCAR program is about 27 percent of the entire budget. The National Guard also spends $12 million on a sponsorship of IndyCar driver Graham Rahal.

At issue is the National Guard's inability to tie the sponsorship directly to a specific number — if any — of recruits who enlisted.

"How can you justify the fact that nobody is getting recruited from the NASCAR?" said subcommittee chairman Sen. Claire McCaskill (D-Mo.). "The facts speak for themselves. The data is very clear. You are not getting recruits off NASCAR. This is data that you gave us. … If you were forced to spend less, (can you say) that this isn't something you would immediately look at in terms of deciding this is not the best use of the money?"

Lyons said he is analyzing the programs.

“Sponsorships like NASCAR and IndyCar, which we view as branding programs that raise awareness of the National Guard in the communities, trying to tie that awareness directly down to an individual’s affirmative decision to join the National Guard is elusive,” Lyons said during the hearing. “I share your concern about that.

“That’s why as I look ahead, I want to evaluate these programs.”

The hearing painted a somewhat ominous future for the NASCAR sponsorship, though the House of Representatives has defeated proposed bans on the sponsorships by a 216-202 vote in 2012 and a 289-134 vote in 2013.

Unless there is a ban by Congress, Lyons will ultimately decide whether to sponsor Earnhardt in 2015. He said he expects to make a decision in the next month. Earnhardt has the remaining 18 events for 2015 sponsored by PepsiCo and Nationwide Insurance.

It isn’t rare in the sports marketing world for new company leadership to re-evaluate significant sports sponsorship spending, and Lyons said he had never been to a NASCAR or IndyCar race.

“I would like to know what are good metrics to use to measure the effectiveness of sports sponsorship programs," Lyons said. "And that’s what I’m focused in on. … I'm trying to analyze these programs for exactly the reasons (committee members) are saying — are they achieving the intended effect, are they the best use of our taxpayer dollars and is that the right thing to be doing?"

The $32 million the National Guard spends on NASCAR is for 20 races, plus activation of programs that revolve around the Hendrick Motorsports sponsorship. The National Guard would get some money back through merchandise sales, though that was not discussed during the hearing.

According to a 2013 National Guard study, 90 percent of those who enlisted or re-enlisted since 2007 were exposed to the Guard through recruiting or retention materials featuring NASCAR cars and/or drivers. The study also found that NASCAR fans are 20 percent more likely than non-fans to support a friend or family member who pursues military service.

Lyons said Thursday the racing programs are projected to lead to engagement of 35,000 high-school students — Earnhardt spoke at a high school Thursday — and recruiters want to show cars at the recruiting events because they attract attention.

McCaskill said the NASCAR team sponsorship generated fewer than 8,000 leads in 2013, “a far cry” from the 1 million leads needed annually to enlist 50,000 people. She theorized during the hearing that the sponsorships aren’t reaching the key 18-24 demographic because she said only 10 percent of NASCAR viewers are between 18-24 and the average age of an IndyCar fan is 35-54.

“The regular Army ended its sponsorship in NASCAR (of Ryan Newman) in 2012 after concluding that the program had the highest cost per lead in the Army’s portfolio of sponsorships,” McCaskill said. “The Army also cited the fact that only a small portion of the NASCAR audience fell in its target demographic.”

McCaskill opened the hearing to say this wasn’t an anti-motorsports campaign.

“I really like NASCAR,” McCaskill said. “I love the National Guard more than I like NASCAR. This hearing isn’t about demonizing NASCAR or the National Guard. This hearing is simply about return on investment of federal tax dollars.”